Answer:
The added carbon is supplied by acetyl CoA and the 2 eliminated carbons are released as CO2.
Explanation:
TCA cycle or citric acid cycle occurs in the mitocondrial matrix.
The ist step of TCA cycle deals with the formation of citrate molecule bt the addition of Acetyl CoA with oxaloacetate. The acetyl CoA is a 2 carbon compound formed from pyruvate by the catalytic activity of pyruvate dehydrogenase .
The 2 eliminated carbons are released as carbon di oxide or CO2.The CO2 molecule is eliminated during the formation of alpha ketoglutarate from isocitrate .The second CO2 molecule is eliminated when alpha ketoglutarate is converted to succinyl CoA.